This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. BACKGROUND The polycyclic aromatic hydrocarbon (PAH) family includes 100 different compounds. These compounds are formed from natural and synthetic sources that involve high-temperature pyrolytic processes, however, PAHs originating from synthetic sources are quantitatively more important in terms of environmental distribution. Human exposure to PAHs has been attributed to home heating and cooking using coal or wood, cigarette smoking, automobile exhaust emissions, consumption of ontaminated foods, occupational exposure in coke, graphite-electrode and carbon-anode manufacturing industries to mention a few. The toxicity of PAHs has been studied by a number of investigators under in vitro conditions and there have been no attempts to study PAH toxicity in a subchronic regimen. For risk estimation, long-term animal exposure to commonly occurring PAHs is essential. Quantitative risk assessment of PAHs has been hampered by lack of sufficient data sets from animal studies. Information relative to acute and subchronic exposures through ingestion of PAH-contaminated water, food, or soil is vital in assessing the risk to individuals living in areas surrounding hazardous waste sites. Because of the widespread availability of PAHs in the environment and the considerable probability of human exposure, the potential adverse effects of this compound merit investigation. For this pilot project, we assessed the effects of benzo(a)pyrene (BaP), a prototypical PAH, on ovarian function with the following specific aims. SPECIFIC AIMS 1. To determine the bioavailability and toxicokinetics of benzo(a)pyrene in female rats. 2. To determine the effect of BaP treatment on plasma concentrations of gonadal steroids and the pituitary hormones that regulate these steroids during the rat estrous cycle. 3. To determine the effect of BaP on ovarian exocrine function and luteal maintenance. 4. To determine the effect of BaP on fertilization and pre-implantation development.